This comes from a man who KNOWS his stuff (MMI instructor) and has used it for years. He uses the simple food preservative BHT. 1 teaspoon per 20 gallons of fuel. When I asked what it did specifically, he explained it as making a "skim" layer on the top of the fuel, as a type of evaporative "seal".

Guess I'm just an old fashion kind of guy. I use Harley fuel additive with Duralt .

__________________
Ride hard you can rest when you die
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body but rather to skid in broadside thoroughly used up totally worn out and loudly proclaiming man what a ride!
Save The The Montagnard People

I was a mechanic for about 6 years and trained in college for it too. the best thing is that regular gas preservative. More goes on the than evaporation. Fuels slowly react with plastic cans, bacteria does attack gasoline. I work in power generation for a living, you can tell how much bateria are eating by checking the temperature. Inside a large 1-3 million gallon tank, temps can rise by 5 degrees degrees from theri "eating". Gasoline additive is more complex, but diesel additive is a type of antibiotic. Also, UV sterilizers are used by some power plant storage tanks.

Sta-bil is good stuff and so is Pri-g and pri-d this needs editing but it is from a class I am doing on preparedness for my local comunity center.

Does fuel really spoil? Well yes it does but not in the way that many people believe that it does. Fuel that sits does not lose its energy content or its anti-knock index (octane rating as long as it does not evaporate) if you strike a match to old fuel it will indeed burn however the properties of fuel can change if the storage is accompanied by evaporation. The lightends from fuel evaporate lights ends are what allows the fuel to vaporize when cool and allows for easy starting of internal combustion engine so as fuel sits it can loose its ability to start an engine. The ability for the fuel to vaporize is what determines it’s volatility

What is gasoline? Gasoline is a derivative of crude oil it is considered a light oil and is produced through the refining process. Crude oil is commonly bought and sold by the barrel a barrel of oil is 42 gallons from that barrel of oil the refinery will produce about 22 gallons of gasoline.

When you heat crude oil it starts to separate by molecular weight and you can separate it into its individual parts.

The lightest of these parts are crude gases such as Methane, Ethane, Propane, and Butane these gases are not only used as fuels but they are also used in the production of plastics.

Next by molecular weight we have Naphtha’s AKA Lightends these are the part that is reblended in to the gasoline so that it will more easily start a internal combustion engine.

Next we have the Gasoline it makes up about 50% of each barrel of crude oil and it is actually a blend of olefins and diolefins and the lightends,

Then we have Kerosene AKA Jet Fuel it is heavier and less volatile then gasoline but it also contains more BTU’s of energy then it’s lighter cousin gasoline.

Then we have Diesel or Heating oil it is even less volatile then Gasoline. However It contains more energy by volume then does gasoline. Diesel has approximately 147000 BTUs per gallon and gasoline has 125000 BTUs per gallon.

Next are the lube oils or heavy oils these oils are both less volatile and they contain less BTU’s of energy by weight they can be any number of things from motor oil to grease.

The last group to be sorted out of the crude oil are the tars waxes and asphalt which is just a blend of tar and an agraget such as crushed stone.

How do you compare the energy content?
When we talk about the energy content of these petrol chemicals we do so in relation to how many BTU’s the substance at hand contains in relation to the volume in gallon’s.

So what happens to stored fuel?

1. Evaporation and loss of volatility:
The gasoline’s that we burn in our cars are a blend of hydrocarbons the refiners first clean the crude oil that will become gasoline impurities such as sulfur are removed and then it is distilled in an distillation tower or column, in this tower the different parts separate by there molecular waits and are separated in to separate tanks the refiner then blends these components back into different grades of gasoline, When evaporation is allowed the light ends that vaporize at low temperatures are lost this in turn leave the hydrocarbons that need higher temperatures to vaporize remember gasoline does not burn in it’s liquid state only the vapors combust so with the light ends gone you no longer have a fuel that will start a motor. On the other side of the coin the fuel is less likely to cause engine knock because it is less likely to ignite prematurely.

2. Oxidation:
As stated above gasoline is a blend of stable hydrocarbons but there are also some unstable hydrocarbons as well the two that concern us the most are the olefins and diolefins when these two combine with oxygen they take on some of the molecules creating long chain olefins and diolefins also known as “gum” in the fuel this is the cause of your fuel becoming darker over time. Eventually these gums will foul fuel filters, fuel injectors, and carburetors they also will form deposits when they are burned on valves and pistons. This is where fuel stabilizers come into play they effect fuel in two major ways first they act as a barrier preventing these long chain olefins and diolefins from forming they also act as an anti microbial agent.

3. Contamination:
The next big problem is contamination this can be from water microbes or just plain old dirt and dust in the fuel all of these will degrade the fuel and can lead to it being unusable water forms in fuel when the tank it is in is vented as the fuel in the tank warms it expands pushing the fuel vapor out there by pushing out some of the all important lightends then as it cools it contracts sucking in air as the air picks up fuel vapor the water in it condenses back in to liquid water and it ends up in your fuel microbes form in the interface between the water and the fuel the byproduct of these microbes is what we call sludge this is the same sludge you see in the bottom of you gas cans occasionally. Again this is where Fuel Stabilizer comes in it has an anti microbial element that prevents the microbes from growing.

Ok so how do we store fuel for the long term? Well first of all the shelf life of gasoline is about two years if stored properly. And that is with the addition of fuel stabilizer adding more fuel stabilizer every two years will not help it to store longer mainly because eventually the olefins and diolefins will start to form long chains, stabilizers only slow the process they can not stop it completely.

1. Reformulated Fuel.
If you can get reformulated fuel (they sell it in California) it stores much better then does regular gasoline. Why? Because they remove the olefins from the fuel and they also replace some of the lightends with stabilized oxygenators that do not evaporate with the lightends. With stabilizers these reformulated fuels can last three years.

2. Keep your fuel Cool.
The cooler that fuel is the longer it will last warm temperatures promote the formation of long chain olefins and diolefins it also promotes the vaporization of the lightends in the fuel.

4. Don’t fill your container more than 95% full.
This allows room for the fuel to expand and contract with out causing a pressure rupture of the container.

5. Only put fuel into clean dry containers.
Obviously the better the conditions are when you start the better your end result also make sure that the container is made and approved for the storage of gasoline.

6. Never store fuel in a inhabited building.
Gasoline is very flammable and errant fumes do readily combust if you fill a room with gasoline vapors, air and then give it an ignition source you will have a very intense flash over or explosion.

7. Never store fuel in an attached garage or shed.
Obviously if your attached shed blows up and burns so will your home if it is attached.

8. When you use fuel that has been stored for more that 3 months filter it before you poor it into the fuel tank that it will be used from a good way to do this is to simply poor the fuel through a couple of coffee filters.

Fuel Stabilizers:
Are made from fuel distillates such as Cas # 64742-47-48 what is this well I really don’t know but what it is not is alcohol adding alcohol to your fuel will not stabilize it. It also is not Ether that is what starting fluid is and adding it to your fuel will only cause the lightends to evaporate more quickly.

Disposing of old Fuel.

Well the only safe way to dispose of old fuel is to use it up, Dumping old fuel in sewers or drains is 1 illegal and 2 very dangerous as it is likely to end up in the aquifer or in stream or rivers Waste water treatment plants are not equipped to deal with petrochemicals and it generally gets past straight through to the environment. It could also end up causing an explosion and or fire at the sewer treatment plant.

Restoring Old Fuel.

Well you cant really restore gasoline but you can still use it the first thing too do to make it usable is to filter the fuel through several layers of coffee filters to remove the fine particulate and some of the gum, Next mix it 3 to 1 with new fuel 3 Parts new to 1 part old. This should thin out the remaining gums in the fuel it will also raise the percentage of light ends to a more acceptable level.

So what do you do if the only fuel you can get has spoiled well firstly filter it the best you can the clearer that you can get it the better. Next if it will not readily start you engine you can use some starting fluid to get it running once it is started it should keep running until it clogs something up.. (and it will eventually clog something up.) you can also try to add an octane booster such as 104+ this is a can of Naphtha’s just waiting to vaporize for you.. Also if you take a look at a box of mothball you may be surmised at what they are they contain Naphtha’s and can be of some use. Also if the fuel has been in a vehicle or in the equipment add a good quality fuel system cleaner to it as well as a bottle of HEET fuel system antifreeze and dryer.

If there is water in the fuel you will need to decant the fuel leaving the water behind you can do this with a small pump or siphon it is best to put your fuel into a clear container first and let the water settle out then you can siphon off the gas and leave the water behind.

Fuel Storage Myths

Does Reformulated fuel attract more moisture I.e. water then non reformulated fuel.. the theory goes like this reformulated fuels have alcohol in them and it attracts more moisture in to your fuel..

Well it is false alcohol does not magically attract moisture it is not inherently hydroscopic when alcohol is esterifies through soaponification then it can become hydroscopic but ethanol that is blended in to fuels is not inherently hydroscopic. That not to say it wont mix with water because it will but it does not draw water out of the atmosphere as many people would have you believe.

Reformulated fuels are just gasoline with alcohol mixed.

False Reformulated fuel may indeed use ethanol as it’s primary oxygenator but more likely it uses MTBE, ETBE, or TAME or a combination of all of the above. According to the EPA 93.14% of reformulated fuel use a mix of the above oxygenators.

You can test to see if your fuel is OK by lighting a cup of it on fire…

NO! NO! NO! not only is this dangerous but it is totally false. fuel even after it spoils still contains all of the energy that it did prior to spoilage remember you never lose energy it can only be transformed to another form of energy. 30 year old fuel will still burn with all of the ferocity as brand new gasoline. How ever it may not start a internal combustion engine because it lacks the light ends required to easily vaporize at room temperatures.

Fuel stabilizers can reform old fuel and make them like new..

Nope it does not work that way there some stabilizers that contain naphtha but adding some naphtha does not restore your fuel to new condition. You still have gum and sludge problems also the naphtha that is re added is lost very quickly from the fuel.

A large enough container (300 t0 400 gallons) might enable you to get deliveries from a gas supplier, at a discount.

Not usually you will pay the going rate for gasoline unless you are a reseller plus you will pay a delivery fee you may beabel to purchase fuel with out the road tax on it but if you use it on the road you are taking a risk of getting a substantial fine or in some state even forfeiture of the vehicle.

Gas loses approximately one point of octane per month and when it gets below 80 it loses enough combustibility not to work in engines... sta-bil keeps the octane rating from dropping for like 12 months...

Just plain bogus information off the internet. This is the perfect reason you must be meticulous and check all your facts.

If you can keep the gasoline in a container that can be presurized to at least 11psi , it will keep indefinetly. I did chemical packaging/cleanup for a while and it is in one of the safety books.

Completely false and in fact it will speed the formation of gum in your gasoline.

I use sealed 6 gal plastic gas cans with a double shot of Stabl, the cans pressureize them self. The fuel has kept useable for over 2 years in the backup generator's tank (bought it for y2k then the power did not go off for over 2 years) all I did was keep the battery on a tickle charger. Usually I have 40+ gallons of gas and 25 of kerosene in the shop at all times, (hay we live in the country and it's no fun not being able to flush the toilet when the power goes of), the extra fuel never goes to waste with the JD and the Bobcat in use, just keep cycleing the cans and refill each time one goes empty.

This is good advice the only thing to add here is to keep your fuel cool.

I call it my boat, it holds 60 gal. Plus I have a 28 gal can on wheels.

Remember water and venting is the enemy when it come to fuel storage.

Gasoline requires stabilizer, as has been noted. Diesel doesn't.
False.

Diesel fuel is subject to the same degradation as gasoline the only difference is that diesel does not rely on vaporization as does gasoline engines.

Sta-bil is good stuff and so is Pri-g and pri-d this needs editing but it is from a class I am doing on preparedness for my local comunity center.

Does fuel really spoil? Well yes it does but not in the way that many people believe that it does. Fuel that sits does not lose its energy content or its anti-knock index (octane rating as long as it does not evaporate) if you strike a match to old fuel it will indeed burn however the properties of fuel can change if the storage is accompanied by evaporation. The lightends from fuel evaporate lights ends are what allows the fuel to vaporize when cool and allows for easy starting of internal combustion engine so as fuel sits it can loose its ability to start an engine. The ability for the fuel to vaporize is what determines it’s volatility

What is gasoline? Gasoline is a derivative of crude oil it is considered a light oil and is produced through the refining process. Crude oil is commonly bought and sold by the barrel a barrel of oil is 42 gallons from that barrel of oil the refinery will produce about 22 gallons of gasoline.

When you heat crude oil it starts to separate by molecular weight and you can separate it into its individual parts.

The lightest of these parts are crude gases such as Methane, Ethane, Propane, and Butane these gases are not only used as fuels but they are also used in the production of plastics.

Next by molecular weight we have Naphtha’s AKA Lightends these are the part that is reblended in to the gasoline so that it will more easily start a internal combustion engine.

Next we have the Gasoline it makes up about 50% of each barrel of crude oil and it is actually a blend of olefins and diolefins and the lightends,

Then we have Kerosene AKA Jet Fuel it is heavier and less volatile then gasoline but it also contains more BTU’s of energy then it’s lighter cousin gasoline.

Then we have Diesel or Heating oil it is even less volatile then Gasoline. However It contains more energy by volume then does gasoline. Diesel has approximately 147000 BTUs per gallon and gasoline has 125000 BTUs per gallon.

Next are the lube oils or heavy oils these oils are both less volatile and they contain less BTU’s of energy by weight they can be any number of things from motor oil to grease.

The last group to be sorted out of the crude oil are the tars waxes and asphalt which is just a blend of tar and an agraget such as crushed stone.

How do you compare the energy content?
When we talk about the energy content of these petrol chemicals we do so in relation to how many BTU’s the substance at hand contains in relation to the volume in gallon’s.

So what happens to stored fuel?

1. Evaporation and loss of volatility:
The gasoline’s that we burn in our cars are a blend of hydrocarbons the refiners first clean the crude oil that will become gasoline impurities such as sulfur are removed and then it is distilled in an distillation tower or column, in this tower the different parts separate by there molecular waits and are separated in to separate tanks the refiner then blends these components back into different grades of gasoline, When evaporation is allowed the light ends that vaporize at low temperatures are lost this in turn leave the hydrocarbons that need higher temperatures to vaporize remember gasoline does not burn in it’s liquid state only the vapors combust so with the light ends gone you no longer have a fuel that will start a motor. On the other side of the coin the fuel is less likely to cause engine knock because it is less likely to ignite prematurely.

2. Oxidation:
As stated above gasoline is a blend of stable hydrocarbons but there are also some unstable hydrocarbons as well the two that concern us the most are the olefins and diolefins when these two combine with oxygen they take on some of the molecules creating long chain olefins and diolefins also known as “gum” in the fuel this is the cause of your fuel becoming darker over time. Eventually these gums will foul fuel filters, fuel injectors, and carburetors they also will form deposits when they are burned on valves and pistons. This is where fuel stabilizers come into play they effect fuel in two major ways first they act as a barrier preventing these long chain olefins and diolefins from forming they also act as an anti microbial agent.

3. Contamination:
The next big problem is contamination this can be from water microbes or just plain old dirt and dust in the fuel all of these will degrade the fuel and can lead to it being unusable water forms in fuel when the tank it is in is vented as the fuel in the tank warms it expands pushing the fuel vapor out there by pushing out some of the all important lightends then as it cools it contracts sucking in air as the air picks up fuel vapor the water in it condenses back in to liquid water and it ends up in your fuel microbes form in the interface between the water and the fuel the byproduct of these microbes is what we call sludge this is the same sludge you see in the bottom of you gas cans occasionally. Again this is where Fuel Stabilizer comes in it has an anti microbial element that prevents the microbes from growing.

Ok so how do we store fuel for the long term? Well first of all the shelf life of gasoline is about two years if stored properly. And that is with the addition of fuel stabilizer adding more fuel stabilizer every two years will not help it to store longer mainly because eventually the olefins and diolefins will start to form long chains, stabilizers only slow the process they can not stop it completely.

1. Reformulated Fuel.
If you can get reformulated fuel (they sell it in California) it stores much better then does regular gasoline. Why? Because they remove the olefins from the fuel and they also replace some of the lightends with stabilized oxygenators that do not evaporate with the lightends. With stabilizers these reformulated fuels can last three years.

2. Keep your fuel Cool.
The cooler that fuel is the longer it will last warm temperatures promote the formation of long chain olefins and diolefins it also promotes the vaporization of the lightends in the fuel.

4. Don’t fill your container more than 95% full.
This allows room for the fuel to expand and contract with out causing a pressure rupture of the container.

5. Only put fuel into clean dry containers.
Obviously the better the conditions are when you start the better your end result also make sure that the container is made and approved for the storage of gasoline.

6. Never store fuel in a inhabited building.
Gasoline is very flammable and errant fumes do readily combust if you fill a room with gasoline vapors, air and then give it an ignition source you will have a very intense flash over or explosion.

7. Never store fuel in an attached garage or shed.
Obviously if your attached shed blows up and burns so will your home if it is attached.

8. When you use fuel that has been stored for more that 3 months filter it before you poor it into the fuel tank that it will be used from a good way to do this is to simply poor the fuel through a couple of coffee filters.

Fuel Stabilizers:
Are made from fuel distillates such as Cas # 64742-47-48 what is this well I really don’t know but what it is not is alcohol adding alcohol to your fuel will not stabilize it. It also is not Ether that is what starting fluid is and adding it to your fuel will only cause the lightends to evaporate more quickly.

Disposing of old Fuel.

Well the only safe way to dispose of old fuel is to use it up, Dumping old fuel in sewers or drains is 1 illegal and 2 very dangerous as it is likely to end up in the aquifer or in stream or rivers Waste water treatment plants are not equipped to deal with petrochemicals and it generally gets past straight through to the environment. It could also end up causing an explosion and or fire at the sewer treatment plant.

Restoring Old Fuel.

Well you cant really restore gasoline but you can still use it the first thing too do to make it usable is to filter the fuel through several layers of coffee filters to remove the fine particulate and some of the gum, Next mix it 3 to 1 with new fuel 3 Parts new to 1 part old. This should thin out the remaining gums in the fuel it will also raise the percentage of light ends to a more acceptable level.

So what do you do if the only fuel you can get has spoiled well firstly filter it the best you can the clearer that you can get it the better. Next if it will not readily start you engine you can use some starting fluid to get it running once it is started it should keep running until it clogs something up.. (and it will eventually clog something up.) you can also try to add an octane booster such as 104+ this is a can of Naphtha’s just waiting to vaporize for you.. Also if you take a look at a box of mothball you may be surmised at what they are they contain Naphtha’s and can be of some use. Also if the fuel has been in a vehicle or in the equipment add a good quality fuel system cleaner to it as well as a bottle of HEET fuel system antifreeze and dryer.

If there is water in the fuel you will need to decant the fuel leaving the water behind you can do this with a small pump or siphon it is best to put your fuel into a clear container first and let the water settle out then you can siphon off the gas and leave the water behind.

Fuel Storage Myths

Does Reformulated fuel attract more moisture I.e. water then non reformulated fuel.. the theory goes like this reformulated fuels have alcohol in them and it attracts more moisture in to your fuel..

Well it is false alcohol does not magically attract moisture it is not inherently hydroscopic when alcohol is esterifies through soaponification then it can become hydroscopic but ethanol that is blended in to fuels is not inherently hydroscopic. That not to say it wont mix with water because it will but it does not draw water out of the atmosphere as many people would have you believe.

Reformulated fuels are just gasoline with alcohol mixed.

False Reformulated fuel may indeed use ethanol as it’s primary oxygenator but more likely it uses MTBE, ETBE, or TAME or a combination of all of the above. According to the EPA 93.14% of reformulated fuel use a mix of the above oxygenators.

You can test to see if your fuel is OK by lighting a cup of it on fire…

NO! NO! NO! not only is this dangerous but it is totally false. fuel even after it spoils still contains all of the energy that it did prior to spoilage remember you never lose energy it can only be transformed to another form of energy. 30 year old fuel will still burn with all of the ferocity as brand new gasoline. How ever it may not start a internal combustion engine because it lacks the light ends required to easily vaporize at room temperatures.

Fuel stabilizers can reform old fuel and make them like new..

Nope it does not work that way there some stabilizers that contain naphtha but adding some naphtha does not restore your fuel to new condition. You still have gum and sludge problems also the naphtha that is re added is lost very quickly from the fuel.

A large enough container (300 t0 400 gallons) might enable you to get deliveries from a gas supplier, at a discount.

Not usually you will pay the going rate for gasoline unless you are a reseller plus you will pay a delivery fee you may beabel to purchase fuel with out the road tax on it but if you use it on the road you are taking a risk of getting a substantial fine or in some state even forfeiture of the vehicle.

Gas loses approximately one point of octane per month and when it gets below 80 it loses enough combustibility not to work in engines... sta-bil keeps the octane rating from dropping for like 12 months...

Just plain bogus information off the internet. This is the perfect reason you must be meticulous and check all your facts.

If you can keep the gasoline in a container that can be presurized to at least 11psi , it will keep indefinetly. I did chemical packaging/cleanup for a while and it is in one of the safety books.

Completely false and in fact it will speed the formation of gum in your gasoline.

I use sealed 6 gal plastic gas cans with a double shot of Stabl, the cans pressureize them self. The fuel has kept useable for over 2 years in the backup generator's tank (bought it for y2k then the power did not go off for over 2 years) all I did was keep the battery on a tickle charger. Usually I have 40+ gallons of gas and 25 of kerosene in the shop at all times, (hay we live in the country and it's no fun not being able to flush the toilet when the power goes of), the extra fuel never goes to waste with the JD and the Bobcat in use, just keep cycleing the cans and refill each time one goes empty.

This is good advice the only thing to add here is to keep your fuel cool.

I call it my boat, it holds 60 gal. Plus I have a 28 gal can on wheels.

Remember water and venting is the enemy when it come to fuel storage.

Gasoline requires stabilizer, as has been noted. Diesel doesn't.
False.

Diesel fuel is subject to the same degradation as gasoline the only difference is that diesel does not rely on vaporization as does gasoline engines.